In his philosophical phase, Walker Percy meditated deeply on perception and knowledge, and their relationship to symbols and language. This superb passage is from a 1958 essay in the Journal of Philosophy :

“If I see an object at some distance and do not quite recognize it, I may see it, actually see it, as a succession of different things, each rejected by the criterion of fit as I come closer, until one is positively certified. A patch of sunlight in a field I may actually see as a rabbit - a seeing which goes much further than the guess that it may be a rabbit; no, the perceptual gestalt is so construed, actually stamped by the essence of rabbitness: I could have sworn it was a rabbit. On coming closer, the sunlight pattern changes enough so that the rabbit-cast is disallowed. The rabbit vanishes and I make another cast: it is a paper bag, and so on. But most significant of all, even the last, the ‘correct’ recognition is quite as mediate an apprehension as the incorrect ones; it is also a cast, a pairing, an approximation. And let us note in passing that even though it is correct, even though it is borne out by all indices, it may operate quite as effectively to conceal as to discover. When I recognize a strange bird as a sparrow, I tend to dispose if the bird under its appropriate formulation: it is only a sparrow.”